In recent years, the world has shown considerable concerns about environmental degradation accompanied by urban expansion. In terms of size, Bogura is equivalent to most of the major cities in Bangladesh, yet no thermal and ecological assessment has ever been conducted here. This study uses multitemporal Landsat satellite images between 2001 and 2020 to investigate the thermal and ecological conditions of Bogura Sadar (sub-district). Land surface temperature (LST) is obtained from Landsat images using the widely used radiative transfer equation. The thermal and ecological conditions are evaluated by computing urban heat island (UHI) and urban thermal field variance index (UTFVI) from LST data. The influence of vegetation, built-area, water-body, and bare soil on LST are examined using land cover indices through pixel-level multivariate linear regression analysis. According to the findings of this sub-district-scale (urban and rural areas) study, the mean LST has increased by 0.62 °C in the last 20 years. As per local administrative-wise findings, LST has increased in most areas, regardless of their urban or rural function. The difference between the urban area and the rest of the surroundings was significant (1.74 °C) in 2020. In 2001, UHI affected area was 5.65 km, which expanded to 8.84 km in 2020. Thermal and ecological conditions are worse in urban areas than its surrounding areas. The regression models of the LST and land cover indices could explain more than half (R: 0.66 to 0.73) of LST variation over the years. Land cover could explain the LST in 2020 to the least extent implying that anthropogenic activities have greater influence than earlier. Land cover could explain less than half of the LST variation in the urban area.

中文翻译：

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基于地表温度和量化多变量控制因素的孟加拉国博古拉的热和生态评估


近年来，世界对城市扩张带来的环境恶化表现出相当大的担忧。就规模而言，博古拉相当于孟加拉国大多数主要城市，但从未在这里进行过热力和生态评估。本研究使用 2001 年至 2020 年多时相 Landsat 卫星图像来调查博古拉萨达尔（分区）的热力和生态状况。陆地表面温度 (LST) 是使用广泛使用的辐射传输方程从陆地卫星图像中获得的。通过根据LST数据计算城市热岛（UHI）和城市热场方差指数（UTFVI）来评估热力和生态条件。通过像素级多元线性回归分析，使用土地覆盖指数检查植被、建筑面积、水体和裸土对地表温度的影响。根据这项分区规模（城市和农村地区）研究的结果，过去 20 年平均地表温度上升了 0.62 °C。根据当地行政部门的调查结果，大多数地区的土地覆盖税都增加了，无论其功能是城市还是农村。 2020年城区与周边地区温差显着（1.74℃）。2001年城市热岛影响面积为5.65平方公里，2020年扩大至8.84平方公里。城区热力和生态条件较差。其周边地区。 LST和土地覆盖指数的回归模型可以解释一半以上（R：0.66至0.73）多年来LST变化。土地覆盖可以在最小程度上解释 2020 年的地表温度，这意味着人类活动的影响比之前更大。土地覆盖只能解释城市地区不到一半的地表温度变化。